The proliferation of primary human dermal fibroblasts treated with increasing concentrations of hIGF-I was assessed. After 72-hour treatment with hIGF-I cells were incubated with a tetrazolium salt and the OD450 - OD650 was determined.

Gallery: Human Insulin-like Growth Factor I (hIGF-I) #8917

The purity of recombinant hIGF-I was determined by SDS-PAGE of 6 µg reduced (+) and non-reduced (-) recombinant hIGF-I and staining overnight with Coomassie Blue.

The proliferation of primary human dermal fibroblasts treated with increasing concentrations of hIGF-I was assessed. After 72-hour treatment with hIGF-I cells were incubated with a tetrazolium salt and the OD450 - OD650 was determined.

Source / Purification

Product Description

Purity:

>98% as determined by SDS-PAGE of 6 μg reduced (+) and non-reduced (-) recombinant hIGF-I. All lots are greater than 98% pure.

Molecular Formula:

Recombinant hIGF-I has a Met on the amino terminus and has a calculated MW of 7,785. DTT-reduced and non-reduced protein migrate as 6 kDa polypeptides. The expected amino-terminal MGPET of recombinant hIGF-I was verified by amino acid sequencing.

Bioactivity:

The bioactivity of recombinant hIGF-I was determined in a cell proliferation assay using primary human dermal fibroblasts. The ED50 of each lot is between 2-8 ng/ml.

Storage:
Stable in lyophilized state at 4°C for 1 year after receipt. Sterile stock solutions reconstituted with carrier protein are stable at 4°C for 2 months and at -20°C for 6 months. Avoid repeated freeze-thaw cycles.Maintain sterility. Storage at -20°C should be in a manual defrost freezer.

Background

Most circulating endocrine acting IGF-I is produced by hepatocytes, and paracrine or autocrine acting IGF-I is produced by defined cell types within specific tissues (1,2). Many neoplastic cells produce IGF-I, which regulates a number of cellular processes including energy metabolism, proliferation, and cell survival (3,4). IGF-I activity is regulated by one or more of the six extracellular IGF-binding proteins (IGFBPs). IGFBPs bind to IGF-I and most inhibit IGF-I binding to IGF-I receptor (IGFIR) (1,2). Some IGFBPs may increase cell responses to IGF-I. Binding of IGF-I to IGFIR activates the Akt, JNK, and Erk pathways (2). IGF-I and IGFIR are frequently expressed by cancer cells and may contribute to the proliferation and viability of a number of cancer types (1,2).